import React, {Component} from 'react';

export default class Demo extends Component {

  state = {count: 0}

  add = () => {
    // 对象式的setState
    // 1.获取原来的count值
    // const {count} = this.state
    // // 2.更新状态
    // this.setState({count: count + 1}, () => {
    //   console.log(this.state.count)
    // })
    // console.log('12行的输出', this.state.count)

    // 函数式的setState
    this.setState((state, props) => ({count: state.count + 1}), () => {
      console.log(this.state.count)
    })
  }

  render() {
    return (
      <div>
        <h1>当前求和为：{this.state.count}</h1>
        <button onClick={this.add}>点我+1</button>
      </div>
    );
  }
}